The CTN participates with the Division of Pharmacotherapies & Medical Consequences of Drug Abuse (DPMCDA) on a multi-centered trial to compare the effect of buprenorphine/naloxone (Bup/Nx) and methadone (MET) on liver function. This is a randomized, open-label, multi-center, Phase 4 study in participants entering opioid agonist treatment programs at community centers (methadone centers) throughout the country. The trial started in April 2006. Participants will be randomized until at least 300 evaluable participants are be available in both the Bup/Nx and MET study arms. The study will randomize approximately 1200 subjects and is being implemented in 8 sites across 6 Nodes.

This study demonstrated no evidence of liver damage during the initial 6 months of treatment with either BUP or MET, providing further encouragement to physicians to use buprenorphine as an effective treatment option for opioid addiction.